With the rapid evolution of wireless communication technologies, having wireless communication function has become a necessary requirement for an electronic device. However, with the premise of using the low-cost CMOS manufacturing process, the problems of lower breakdown voltage and higher substrate depletion should be overcome. Therefore, in the design of power amplifier, a technical skill of using transformer to conduct power synthesis so as to shrink the size of transistors and improve the output power has been proposed in conventional skills in the art.
A three-dimensional structured power amplifying apparatus has been proposed in conventional art, the three dimensional structured power amplifying apparatus uses a power amplifier with symmetrical structure to receive feed-in signals, and amplifying the feed-in signals to reduce a loss on power allocation. Also, the three dimensional structured power amplifying apparatus could collect the signals to the center of the symmetrical structure, so that the in-phase signals could be summed.
However, the above-described three-dimensional structured power amplifying apparatus could only process input signals in one signal frequency bands, under the requirement of an electronic device should have the ability of processing input signals in multi-frequency bands, providing a new type of power amplifying apparatus has become an important issue for designers.